The present invention relates to a catheter assembly which is used by being inserted into a heart or a peripheral tissue thereof, particularly, a left or right coronary artery (hereinafter also referred to simply as “the coronary artery”). More specifically, the present invention relates to a guiding catheter for guiding a procedure catheter such as a dilation catheter for PTCA, a stent delivery catheter, etc. to a target site of a blood vessel, or an angiography catheter for injecting a contrast medium to a target site of a blood vessel.
In selective angiography, for example, in the case of obtaining an angiographic image of the right coronary artery, it has been a common practice to insert the distal end of a catheter into the inlet of the right coronary artery, to inject a contrast medium through the catheter, and to obtain a selective angiographic image, for diagnosing the disease of the coronary artery. In such a case, a catheter assuming such a distal end shape as to permit easy insertion of the catheter into the right coronary artery is selected and used. Examples of the catheters designed by paying attention to the differences in the distal end shape include the Judkins type and the Anplatz type. Even in a specified one of these types, for example, in the Judkins type catheters, the catheter for the right coronary artery and the catheter for the left coronary artery differ from each other in the distal end shape.
Thus, different catheters must be selectively and appropriately used according to the difference in the target site (angiography site), namely, the difference between the right coronary artery and the left coronary artery. In addition, in the case of a patient having a blood vessel assuming a special anatomical shape, a further different catheter for exclusive use must be used.
Therefore, a great variety of catheters must be prepared in advance. Particularly in the case of angiography of both the right coronary artery and the left coronary artery, it is necessary to obtain an angiographic image of the right coronary artery by use of a catheter for right coronary artery, then replace the catheter with a catheter for left coronary artery, and obtain an angiographic image of the left coronary artery. Accordingly, the operation requires much labor and time, and exerts an increased burden on the patient.
In order to cope with this problem, a conventional catheter assembly has a structure based on a catheter having a shape called the left Judkins shape, in which a slidable outer jacket is fitted over the catheter, and the angular shape of the catheter assembly is varied by moving the outer jacket, so as to provide the catheter assembly with the functions of both a catheter having the left Judkins shape and a catheter having the right Judkins shape, whereby the need for the catheter replacing operation and the attendant operations is eliminated (see, for example, Japanese Patent Laid-open No. Hei 9-285546).
However, such a catheter assembly as this has the problem that, although the catheter assembly has a shape suitable for enabling the insertion thereof to a target site such as the right coronary artery and the left coronary artery, the shape is not suitable for holding (fixing) the catheter assembly in the target site. Therefore, there has been the problem that the catheter assembly inserted to the target site may slip off from the target site.
It is an object of the present invention to provide a catheter assembly which comprises, in a double form, two catheters different from each other in distal end portion shape, whereby it is possible to attain both the easiness of reaching the site in which the distal end portion is to be inserted and be made to indwell and enhancement of the fixing force for fixing the distal end portion in the site.